Hydrocarbon fluids such as oil and natural gas are obtained from a subterranean geologic formation, referred to as a reservoir, by drilling a wellbore that penetrates the hydrocarbon-bearing formation. Once a wellbore is drilled, various forms of well completion components may be installed to control and enhance efficiency of producing fluids from the reservoir. In various subsea applications, a vertical Christmas tree is installed at a subsea wellhead and combined with a tubing hanger. A seal is formed along an exterior of the tubing hanger via a plurality of seals, but difficulties sometimes arise with respect to adequately pressure testing the tubing hanger seals.